P1 matter

• What is the Greek model of the atom?

  A model that describes atoms as indivisible particles
• What is Rutherford's model of the atom?

  A model that describes the atom as having a dense nucleus surrounded by electrons
• What is the Plum pudding model?

  A model that depicts the atom as a sphere of positive charge with electrons embedded in it
• What did Rutherford's experiment demonstrate?

  That atoms have a dense nucleus
• How did Rutherford's experiment lead to a new theory of the atom?

  It showed that most of the atom is empty space with a small, dense nucleus
• How can you represent a solid, liquid, and gas using particle theory?

  By drawing closely packed particles for solids, loosely packed for liquids, and widely spaced for gases
• How do solids, liquids, and gases change into one another?

  By gaining or losing energy, which affects particle movement
• Why do changes of state occur using energy?

  Energy is required to overcome intermolecular forces during state changes
• What are the two things energy can do to a substance?

  Increase temperature or change state
• What are heating curves?

  Graphs that show the temperature of a substance as it is heated over time
• How do you explain heating curves?

  They illustrate the relationship between temperature and time during heating and phase changes
• How do you draw a heating curve for a material?

  By plotting temperature on the y-axis and time on the x-axis, showing phases and temperature changes
• What is the definition of specific heat capacity?

  The amount of energy required to raise the temperature of 1 kg of a substance by 1°C
• How do you calculate the specific heat capacity of a material?

  By rearranging the formula $c =$$\frac{Q}{m\Delta T}$
• How can you carry out more difficult calculations on specific heat capacity?

  By applying the same principles to different materials and conditions
• What is specific latent heat?

  The amount of energy required to change the state of a substance without changing its temperature
• How do you calculate how much energy a change in state needs?

  Using the formula $Q =$$mL$, where $L$ is the specific latent heat
• Why is it worse to be burnt by steam at 100°C than water at the same temperature?

  Because steam contains more energy due to the latent heat of vaporization
• How do particles in gases exert pressure?

  By colliding with the walls of their container
• How do temperature and volume affect pressure in gases?

  Increasing temperature increases pressure, while increasing volume decreases pressure
• Why does pressure increase as volume decreases and temperature increases?

  Because particles collide more frequently with the walls of the container
• What happens to a balloon when it is placed in a freezer?

  The balloon shrinks as the gas inside cools and the pressure decreases.
• What is the relationship between pressure and volume in gases?

  Pressure and volume are inversely related; as one increases, the other decreases.
• How can you calculate the pressure of a gas?

  Pressure can be calculated using the formula $P =$$\frac{F}{A}$, where $P$ is pressure, <latex{F}</latex> is force, and $A$ is area.
• What happens to gas particles when they are compressed?

  The gas particles move closer together and collide more frequently.
• Why does a gas heat up when it is compressed?

  Gas heats up during compression due to the increase in kinetic energy from particle collisions.
• What does density depend on?

  Density depends on mass and volume.
• How can you calculate the density of an object?

  Density can be calculated using the formula $\text{Density} =$$\frac{\text{Mass}}{\text{Volume}}$.
• How do you measure the density of a regular object in an experiment?

  Measure the mass using a scale and the volume using a ruler, then calculate density.
• How do you measure the density of an irregular object in an experiment?

  Use water displacement to measure the volume and a scale for mass, then calculate density.
• How do you measure the density of a liquid in an experiment?

  Measure the mass of a known volume of liquid using a scale and a graduated cylinder.
• Why can't you measure the density of an irregular object that floats?

  Because it displaces a volume of water equal to its weight, not its volume.
• Why does pressure increase with depth in a fluid?

  Pressure increases with depth due to the weight of the fluid above.
• What is the equation for fluid pressure?

  Fluid pressure can be calculated using $P =$$\rho g h$, where <latex\rho</latex> is density, $g$ is acceleration due to gravity, and $h$ is depth.
• What happens to your lungs and ears as you go deeper underwater?

  Your lungs compress and your ears feel pressure due to increased water pressure.
• How can you link the gas pressure equation to the fluid pressure equation?

  Both equations relate pressure to the properties of the substance, with gas pressure depending on volume and temperature, while fluid pressure depends on depth and density.
• How does atmospheric pressure change with height?

  Atmospheric pressure decreases with height.
• Why does atmospheric pressure decrease with height?

  Atmospheric pressure decreases with height because there is less air above to exert pressure.
• Why doesn't atmospheric pressure have an equation?

  Atmospheric pressure varies with weather conditions and altitude, making it complex to define with a single equation.
• Why does hot water boil in a vacuum chamber?

  Hot water boils in a vacuum chamber because the reduced pressure lowers the boiling point of water.